Selection of TNF-alpha binding affibody molecules using a beta-lactamase protein fragment complementation assay

Protein fragment complementation assays (PCAs) based on different reporter proteins have been described as powerful tools for monitoring dynamic protein-protein interactions in living cells. The present study describes the construction of a PCA system based on genetic splitting of TEM-1 beta-lactamase for the selection of proteins specifically interacting in the periplasm of Escherichia coli bacterial cells, and its application for the selection of affibody molecules binding human tumour necrosis factor-alpha (TNF-alpha) from a combinatorial library. Vectors encoding individual members of a naïve 10(9) affibody protein library fused to a C-terminal fragment of the beta-lactamase reporter were distributed via phage infection to a culture of cells harbouring a common construct encoding a fusion protein between a non-membrane anchored version of a human TNF-alpha target and the N-terminal segment of the reporter. An initial binding analysis of 29 library variants derived from surviving colonies using selection plates containing ampicillin and in some cases also the beta-lactamase inhibitor tazobactam, indicated a stringent selection for target binding variants. Subsequent analyses showed that the binding affinities (K(D)) for three selected variants studied in more detail were in the range 14-27 nm. The selectivity in binding to TNF-alpha for these variants was further demonstrated in both a cross-target PCA-based challenge and the specific detection of a low nm concentration of TNF-alpha spiked into a complex cell lysate sample. Further, in a biosensor-based competition assay, the binding to TNF-alpha of three investigated affibody variants could be completely blocked by premixing the target with the therapeutic monoclonal antibody adalimumab (Humira), indicating overlapping epitopes between the two classes of reagents. The data indicate that beta-lactamase PCA is a promising methodology for stringent selection of binders from complex naïve libraries to yield high affinity reagents with selective target binding characteristics.

High incidence of vascular reconstructions in socioeconomically deprived areas of an urban Swedish population

BACKGROUND

In Malmö approximately 250,000 citizens live in 17 administrative areas with substantial socioeconomic differences. At the single centre for arterial reconstruction, Malmö University Hospital, all procedures are registered prospectively.

METHODS

Between 1987 and 2002, 1832 Malmö citizens underwent reconstruction for peripheral arterial disease, either intermittent claudication (IC) or critical leg ischaemia (CLI). A socioeconomic score based on migration rate, percentage of residents with foreign citizenship/residents with foreign background, social welfare support dependency and unemployment rate has previously been developed and validated for each area. The relationship between socioeconomic score and area-specific standardized morbidity ratios (SMRs) after vascular reconstruction was analysed by population-weighted linear regression.

RESULTS

The mean incidence of vascular reconstruction was 76 (range 27-106) per 100,000 person years. Age- and sex-adjusted SMRs ranged from 0.57 to 1.39. A strong correlation between SMR and socioeconomic score was found overall (R=0.63; P=0.007), in men (R=0.63; P=0.007) and in women (R=0.58; P=0.039), and for IC (R=0.58; P=0.015) and CLI (R=0.58; P=0.015).

CONCLUSION

In an urban population with similar access to medical care, vascular reconstruction rates varied substantially. High-rate areas were characterized by inferior socioeconomic circumstances and a higher prevalence of smoking, hypertension and obesity.

Rosiglitazone and carotid IMT progression rate in a mixed cohort of patients with type 2 diabetes and the insulin resistance syndrome: main results from the Rosiglitazone Atherosclerosis Study

OBJECTIVE

Insulin resistance is associated with progression of atherosclerosis. We assessed the effect of 12 months of treatment with rosiglitazone (RSG) on the progression of carotid intima-media thickness (IMT) in people with type 2 diabetes mellitus (T2DM) or the insulin resistance syndrome (IRS).

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Malmö University Hospital, Malmö, Sweden.

SUBJECTS

555 subjects (200 with T2DM and 355 nondiabetics with IRS according to EGIR criteria), aged 35-80 years. 447 subjects (165 T2DM and 282 IRS) completed the study.

INTERVENTION

Participants were allocated to placebo or RSG 4 mg for 2 months and then 8 mg daily.

MAIN OUTCOME MEASURE

Change in composite IMT [mean IMT in the common carotid artery (CCA) and maximal IMT in the bulb] was the primary and various other IMT measures were secondary outcome variables.

RESULTS

There was no effect of RSG treatment in the mixed population. In T2DM patients there was a reduced progression of the composite IMT (mean change: 0.041 vs. 0.070 mm, P = 0.07), and of the mean IMT CCA (mean change: -0.005 mm vs. 0.021 mm, P = 0.007). RSG treatment led to significant reductions of HOMA-IR, fasting plasma glucose, HbA1c, PAI-1 activity, fibrinogen, C-reactive protein and matrix metalloproteinase-9.

CONCLUSIONS

In a mixed study population of patients with T2DM and IRS RSG treatment was not associated with a statistically significant reduction of carotid IMT progression rate. Separate analyses of these two patient groups indicated, however, a significant beneficial effect on CCA IMT in T2DM patients but no similar effect in subjects with IRS.

Plasma levels of complement C3 is associated with development of hypertension: a longitudinal cohort study

Hypertension has been associated with raised plasma levels of complement factor 3 and 4 (C3 and C4). The nature of this association is unclear. This population-based longitudinal study explored whether C3 or C4 is associated with development of hypertension. Blood pressure and plasma levels of C3 and C4 were determined in 2178 healthy men, aged 35-50 years, initially without treatment for hypertension. Incidence of hypertension and blood pressure increase over 15.7 (+/-2.2) years follow-up was studied in relation to C3 and C4 at baseline. Among men with initially normal blood pressure (<160/95 mm Hg), incidence of hypertension (>or=160/95 mm Hg or treatment) was 32, 42, 37 and 47%, respectively, for men with C3 in the first, second, third and fourth quartile (trend: P=0.001). This relationship remained significant after adjustment for confounding factors. Among men without blood pressure treatment, systolic BP increase (mean+standard error, adjusted for age, initial blood pressure and follow-up time) was 17.5+0.8, 19.6+0.9, 19.8+0.8 and 20.8+0.8 mm Hg, respectively, in the C3 quartiles (trend: P=0.004). C3 was not associated diastolic blood pressure at follow-up. Although C4 was associated with blood pressure at the baseline examination, there was no relationship between C4 and development of hypertension or future blood pressure increase. It is concluded that C3 in plasma is associated with future blood pressure increase and development of hypertension.

Reduced lung function predicts increased fatality in future cardiac events. A population-based study

OBJECTIVE

Moderately reduced lung function in apparently healthy subjects has been associated with incidence of coronary events. However, whether lung function is related to the fatality of the future events is unknown. This study explored whether reduced forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) in initially healthy men is related to the fatality of the future coronary events.

DESIGN

Prospective cohort study.

SETTING

Population-based study from Malmö, Sweden.

SUBJECTS

A total of 5452 healthy men, 28-61 years of age.

MAIN OUTCOME MEASURES

Incidence of first coronary events was monitored over a mean follow-up of 19 years. The fatality of the future events was studied in relation to FEV and FVC.

RESULTS

A total of 589 men suffered a coronary event during follow-up, 165 of them were fatal during the first day. After risk factors adjustment, low FEV or FVC were associated with incidence of coronary events (fatal or nonfatal) and this relationship was most pronounced for the fatal events. Amongst men who subsequently had a coronary event, the case-fatality rates were higher in men with low FEV or FVC. Adjusted for risk factors, the odds ratio for death during the first day was 1.00 (reference), 1.63 (95% CI: 0.9-3.1), 1.86 (1.0-3.5) and 2.06 (1.1-3.9), respectively, for men with FVC in the 4th, 3rd, 2nd, and lowest quartiles (trend: P < 0.05). FEV showed similar relationships with the fatality rates.

CONCLUSION

Apparently healthy men with moderately reduced lung function have higher fatality in future coronary events, with a higher proportion of coronary heart disease deaths and less nonfatal myocardial infarction.

Area social characteristics and carotid atherosclerosis

OBJECTIVES

To explore the effect of social characteristics of residential areas on carotid atherosclerosis prevalence.

METHODS AND RESULTS

The associations among area social characteristics and B-mode ultrasound determined carotid plaque-score (a semi-quantitative scale measuring the degree of atherosclerosis in the carotid bifurcation area) were cross-sectionally investigated in a general population sample of 4033 men and women. Area socioeconomic circumstances were described through a social deprivation index calculated from migration rate, percentage residents with foreign citizenship among those with foreign background, dependency on social welfare support, and employment rate. Living in socially deprived areas was associated with an increased carotid plaque-score in both men (P for trend = 0.004) and women (P for trend = 0.007). These associations were only slightly reduced after adjustment for individual level indicators with a decrease of the absolute mean difference in carotid plaque-score between worse-off and better-off areas of 9% for men and 13% for women, whereas adjustment for risk factors turned the trend non-significant in women, however, not in men.

CONCLUSIONS

Those living in socially deprived areas in general had more extensive carotid atherosclerosis. However, in these areas there were a substantial number of individuals with low degrees of carotid atherosclerosis and vice versa. Thus, with regard to conceptual ideas of causal inference, the social characteristics of an area seem to be associated with the prevalence of carotid atherosclerosis. However, with regard to benefits of prevention, focusing on geographical areas would probably give a restricted benefit, where only some high-risk individuals would be reached.

The role of low grade inflammation as measured by C-reactive protein levels in the explanation of socioeconomic differences in carotid atherosclerosis

BACKGROUND

The role of inflammation as part of the explanation of socioeconomic differences in carotid atherosclerosis has not been specifically investigated.

METHODS AND RESULTS

The associations between socioeconomic position (SEP), C-reactive protein (CRP), and preclinical carotid atherosclerosis were investigated in a general population sample of 3921 middle-aged Swedish men and women. Common carotid intima-media thickness (IMT) and presence of carotid plaque (focal IMT > 1.2 mm) were determined by B-mode ultrasound. The results showed that low SEP was associated with increased levels of CRP, independently of established risk factors. Furthermore, common carotid IMT increased with increasing CRP-levels. Presence of carotid plaque increased with increasing CRP-levels in men, but not in women. While the socioeconomic differences in carotid IMT were weak, there were associations between low educational level and carotid plaque prevalence with an age- and sex-adjusted odds ratio (OR) of 1.39 (95% CI: 1.21, 1.59). A similar association was seen for having a manual occupation, OR = 1.23 (95% CI: 1.07, 1.42). The age- and sex-adjusted absolute differences in carotid plaque prevalence were 9% with regard to educational level and 7% with regard to occupational status. Adjustment for CRP caused only a minor attenuation of the association between SEP and carotid atherosclerosis.

CONCLUSIONS

The association between SEP and carotid atherosclerosis as measured by carotid IMT and carotid plaque could only to a minor extent be referred to differences in low grade inflammation as measured by CRP.

Multi-factor dimensionality reduction applied to a large prospective investigation on gene-gene and gene-environment interactions

It is becoming increasingly evident that single-locus effects cannot explain complex multifactorial human diseases like cancer. We applied the multi-factor dimensionality reduction (MDR) method to a large cohort study on gene-environment and gene-gene interactions. The study (case-control nested in the EPIC cohort) was established to investigate molecular changes and genetic susceptibility in relation to air pollution and environmental tobacco smoke (ETS) in non-smokers. We have analyzed 757 controls and 409 cases with bladder cancer (n=124), lung cancer (n=116) and myeloid leukemia (n=169). Thirty-six gene variants (DNA repair and metabolic genes) and three environmental exposure variables (measures of air pollution and ETS at home and at work) were analyzed. Interactions were assessed by prediction error percentage and cross-validation consistency (CVC) frequency. For lung cancer, the best model was given by a significant gene-environment association between the base excision repair (BER) XRCC1-Arg399Gln polymorphism, the double-strand break repair (DSBR) BRCA2-Asn372His polymorphism and the exposure variable 'distance from heavy traffic road', an indirect and robust indicator of air pollution (mean prediction error of 26%, P<0.001, mean CVC of 6.60, P=0.02). For bladder cancer, we found a significant 4-loci association between the BER APE1-Asp148Glu polymorphism, the DSBR RAD52-3'-untranslated region (3'-UTR) polymorphism and the metabolic gene polymorphisms COMT-Val158Met and MTHFR-677C>T (mean prediction error of 22%, P<0.001, mean CVC consistency of 7.40, P<0.037). For leukemia, a 3-loci model including RAD52-2259C>T, MnSOD-Ala9Val and CYP1A1-Ile462Val had a minimum prediction error of 31% (P<0.001) and a maximum CVC of 4.40 (P=0.086). The MDR method seems promising, because it provides a limited number of statistically stable interactions; however, the biological interpretation remains to be understood.

Fatality of acute coronary events in relation to hypertension and low-grade inflammation: a population-based cohort study

Hypertension has been associated with increased case-fatality rates among individuals who subsequently suffer from acute coronary events. It is unknown whether inflammation modifies this relationship. This population-based study explored the effects of inflammation and hypertension on incidence of coronary event, and on the fatality of the future events. Blood pressure (BP) and five inflammation-sensitive plasma proteins (ISPs, fibrinogen, orosomucoid, alpha 1-antitrypsin, haptoglobin and ceruloplasmin) were determined in 6071 healthy men. During the mean follow-up of 19 years, 679 men had a first coronary event (non-fatal myocardial infarction or death from coronary heart disease). Of them, 197 (29%) were fatal cases (death during the first day). As expected, hypertension was associated with increased incidence of coronary events and increased proportion of fatal cases. At all levels of BP, high ISPs (> or =2 ISPs in top quartile) significantly added to the incidence of events. Men with high ISPs had the highest case-fatality rates. The difference in case-fatality rate between men with and without high ISPs was, however, significant only in men with normal BP (<130/85 mm Hg) (33 vs 19%, P < 0.05), and not in men with moderate or severe hypertension (> or =160/100 mm Hg) (40 vs 35%, P = 0.32). High ISPs add to the incidence of coronary events at all levels of BP. Hypertension and inflammation are both independently associated with increased case-fatality in subjects who later have an acute coronary event. The influence of ISPs on the case-fatality rate seems to be most important in men with normal BP.

Sex differences in the relationships between BMI, WHR and incidence of cardiovascular disease: a population-based cohort study

OBJECTIVE

Body mass index (BMI) is associated with increased incidence of cardiovascular disease (CVD). However, the risk could be very different for individuals with the same body mass. The present study explored whether regional fat distribution, as measured by waist-hip ratio (WHR), could modify the impact of BMI on the risk of CVD in men and women.

DESIGN

Prospective population-based study.

SUBJECTS

A total of 10 369 men and 16 638 women, 45-73 years old, from general population in Malmö, Sweden.

MEASUREMENTS

All subjects were followed over 7 years for the incidences of first-ever cardiac event (CE) and ischemic stroke in relation to BMI category (<25.0, 25.0-29.9, > or =30.0) and WHR.

RESULTS

The prevalence of overweight and obesity was 39.4 and 13.0%, respectively. During follow-up, 1280 subjects suffered a CVD event (750 CE, 530 ischemic stroke). The risk of CVD in women increased with increasing levels of WHR, irrespective of BMI category. In men, WHR (per 1 s.d. increase) was associated with increased incidence of CVD in those with normal weight (relative risk (RR)=1.24; 95% CI: 1.13-1.37) after adjustments for confounding factors. However, WHR was not related to CVD in overweight men (RR=1.06; 95%CI: 0.94-1.20) or obese men (RR=1.04; 95%CI: 0.87-1.24). A significant interaction was observed between sex and WHR on the CVD risk.

CONCLUSION

The effect of WHR on incidence of CVD is modified by the overall body weight and by gender. WHR adds prognostic information on the cardiovascular risk in women at all levels of BMI, and in men with normal weight.

Survival rate 28 days after hospital admission with first myocardial infarction. Inverse relationship with socio-economic circumstances

OBJECTIVE

To study to what extent geographical differences of the mortality from ischaemic heart disease (IHD) can be accounted for by the 28-day case fatality rate (CFR) following first hospital admittance for acute myocardial infarction (MI) and whether the geographical pattern of survival has any relationship with socio-economic circumstances.

DESIGN

Register-based surveillance study.

SETTING

Seventeen residential areas in Malmö, Sweden.

SUBJECTS

All 5533 patients were admitted during 1986-1995 for a first acute MI at Malmö University Hospital. Main outcome measures. CFR is based on record linkage with national registers. Area-specific cardiovascular and socio-economic scores (SES) are based on previous cross-sectional studies.

RESULTS

In patients below 75 years of age, differences of the 28-day CFR accounted for 20-30% of the geographical variance in mortality from IHD. No corresponding association was found in older age groups. Patients from areas with low SES had the highest CFR, 23.8%. The odds ratios of fatal outcome for patients from areas with median and low SES (versus high SES) were 1.23 (95% CI: 1.01-1.50) and 1.25 (95% CI: 1.03-1.52), respectively (P for trend: 0.060). The strongest correlation was observed in men below 75 years of age (P for trend: 0.007). During the study period there was an improvement of the survival rate for patients from high and medium SES areas but no corresponding change for patients coming from areas having a low SES.

CONCLUSIONS

In patients below 75 years, geographical differences of the mortality from IHD were related to differences of the 28-day CFR following hospital admittance for a first MI. Rates of survival were inversely related to socio-economic circumstances in the patient's residential area.

Incidence of cardiac events in hypertensive men related to adaptive behavior in stressful encounters

The Serial Color Word Test was administered at baseline to 253 hypertensive men participating in the prospective cohort study of cardiovascular diseases "Men born in 1914" in Malmö, Sweden. This test of psychological adaptation to a stressful encounter was used to investigate whether susceptibility to stress moderates the risk of a cardiac event in association with hypertension. Adaptive behavior, as measured by test performance, can be categorized in two dimensions. The regression dimension refers to linear change of time spent in the test session whereas the variability dimension refers to nonlinear change. Both dimensions consist of four different patterns. At follow-up (mean time = 8.2 +/- 3.5 years), the risk of a cardiac event varied between men with different adaptive patterns. One pattern, the Cumulative-Dissociative pattern of the variability dimension, characterized by a discontinuous and fluctuating time-consumption, was associated to an almost three-fold risk of a cardiac event during follow-up (relative risk [RR], 2.99; 95% confidence interval [CI], 1.33 - 6.70, p = .010) after adjustment for medical-, socioeconomic-, and lifestyle-related factors. No association existed between adaptive patterns and overall mortality.

Weight gain in relation to plasma levels of complement factor 3: results from a population-based cohort study

AIMS/HYPOTHESIS

Mice that are deficient for complement factor 3 (C3) have shown resistance to weight gain, despite increased food intake. Cross-sectional studies of humans have reported correlations between C3 and obesity. This longitudinal study explored whether C3 predicts a large weight gain in middle-aged men.

METHODS

Plasma concentrations of C3 and complement factor 4 (C4) were measured in 2,706 non-diabetic healthy men aged between 38 and 50 years, who were re-examined after a mean period of 6.1 years.

RESULTS

After adjustments for initial weight, age, height and follow-up time, the odds of incurring large weight gain (75th percentile, > or =3.8 kg) were 1.00 (reference), 0.96 (95% CI:0.7-1.2), 1.1 (CI:0.9-1.5) and 1.4 (CI:1.1-1.8), respectively, among men with C3 levels in the first, second, third and fourth quartiles (p for trend=0.01) respectively. This relationship remained significant after further adjustments for lifestyle factors (physical inactivity, alcohol, smoking), metabolic factors (glucose or homeostasis model assessment values, cholesterol, triglycerides), inflammatory markers (fibrinogen, haptoglobin, ceruloplasmin, orosomucoid, alpha1-antitrypsin) and for C4. C4 was associated with weight gain after adjustments for initial weight, height, follow-up time and lifestyle factors, but not after adjustments for C3.

CONCLUSIONS/INTERPRETATION

C3 is a risk factor for incurring large weight gain in middle-aged men.

Incidence of stroke is related to carotid IMT even in the absence of plaque

BACKGROUND

The carotid intima-media thickness (IMT) has been associated with incidence of stroke. Whether this association is independent of carotid plaque is controversial.

METHODS AND RESULTS

The associations among B-mode ultrasound determined common carotid IMT, carotid plaque (focal IMT>1.2mm) and incident stroke, were investigated in 5163 Swedish middle-aged men and women over a median follow-up of 7 years. Age and sex-adjusted carotid IMT, and carotid plaque were significantly (p<0.05) related to future stroke. Adjustment for cardiovascular risk factors generally reduced the hazard rate ratios, however more prominently so with regard to the carotid measure of plaque than with IMT. The associations between carotid IMT and stroke remained after adjustment for presence of carotid plaque, and graded associations between carotid IMT and stroke was found both among those with and without carotid plaque.

CONCLUSIONS

In this population-based study, common carotid IMT was associated with incidence of stroke. This relation was independent of presence of carotid plaque.

Dietary habits after myocardial infarction - results from a cross-sectional study

OBJECTIVE

Comparing habitual nutrient intakes in persons with a history of acute myocardial infarction (AMI), and age-matched controls. Design. Cross-sectional study. Subjects. Men and women (525 cases and 1890 matched controls), aged 47-73 years, of the population-based Malmö Diet and Cancer cohort.

METHODS

Nutrient intakes were assessed by a validated modified diet history method. Body fatness was assessed by bioimpedance analysis. Case ascertainment was provided by national and regional registries. Men and women were analysed separately. Median time since AMI was 5.5 years in men and 3.8 years in women. Cases reported lower energy intakes (EIs) than controls, despite having similar basal metabolic rates. After adjustment for total EI, both male and female cases had lower fat intake and higher intake of several micronutrients, such as ascorbic acid, folate, and vitamin E, than controls, the difference being largest in men. Most of the cases reporting dietary change quoted 'disease' as their main reason for change. They had lower EI and lower energy-adjusted intake of fat than other cases.

CONCLUSIONS

Survivors of AMI reported dietary habits more in line with current recommendations, particularly those who afterwards reported having changed their dietary habits. The possible bias introduced by social desirability is discussed.

Prevalence and prognostic significance of asymptomatic peripheral arterial disease in 68-year-old men with diabetes. Results from the population study 'Men born in 1914' from Malmö, Sweden

OBJECTIVE

To assess the prevalence of asymptomatic peripheral arterial disease (PAD) in older men with diabetes and to compare the incidence of cardiac events and deaths in diabetic and non-diabetic men with abnormal and normal systolic ankle-brachial pressure index, respectively.

RESEARCH DESIGN AND METHODS

Population-based cohort of 68-year-old men (n = 474). Diabetes was defined as history of diabetes or a fasting blood glucose > or = 6.1 mmol/l. PAD was defined as an ankle-brachial pressure index (ABI) < 0.9 in either leg. Fourteen-year mortality and cardiac event rates were based on record linkage with regional and national registers.

RESULTS

The prevalence of PAD in men with and without diabetes was 29 and 12%, respectively (p = 0.003). The incidence of cardiac events was 22.9/1000 person years in men free from both diabetes and PAD. In the absence of an abnormal pressure index, diabetes was associated with an event rate of 28.4 (p = 0.469). In the presence of an abnormal index the incidence was 102 (p < 0.001). This pattern remained in the multivariate analysis when other atherosclerotic risk factors were taken into account. Cardiovascular mortality rates similarly differed substantially between diabetic men with and without PAD.

CONCLUSIONS

A fasting blood glucose value above 6.1 mmol/l even in the absence of symptoms indicating diabetes was associated by an increased prevalence of asymptomatic PAD. The cardiovascular risk in diabetes varied widely between men with and without abnormal ankle-brachial pressure index.

Risk of Myocardial Infarction and Stroke in Smokers Is Related to Plasma Levels of Inflammation-Sensitive Proteins

BACKGROUND

The extent to which differences in cardiovascular risk between smokers with similar daily tobacco consumption may be related to plasma levels of inflammation-sensitive proteins (ISP) and whether these proteins are associated with levels of carboxyhemoglobin (COHb%) have not been clarified.

METHODS AND RESULTS

In a population-based cohort of 1489 never smokers, 1685 former smokers, and 2901 current smokers, aged 28 to 61 years, plasma levels of orosomucoid (alpha(1)-acid glycoprotein), alpha(1)-antitrypsin, haptoglobin, fibrinogen, and ceruloplasmin were measured. COHb% levels were available for 2098 of them. Incidence of myocardial infarction, stroke, and death were monitored over 18.7+/-4.7 years. The proportion with high ISP levels (ie, > or =2 ISP in the top quartile) increased progressively with daily tobacco consumption (P<0.01) and COHb% (P<0.01). In all smoking categories, the incidence of stroke, cardiac events, and death was related to ISP. In heavy smokers, high ISP levels were associated with adjusted relative risks of 1.57 (1.05 to 2.35) and 1.50 (1.11 to 2.03) for cardiac events and death, respectively. Corresponding figures for moderate and light smokers were 1.59 (1.13 to 2.24) and 1.14 (0.87 to 1.49), respectively, and 1.32 (0.95 to 1.85) and 1.48 (1.10 to 1.98), respectively.

CONCLUSIONS

ISP levels are related to COHb% in smokers. High levels are associated with an increased cardiovascular risk.

Leg blood flow and long-term cardiovascular prognosis in men with typical and atypical intermittent claudication

OBJECTIVES

To compare leg blood flow and the long-term cardiovascular prognosis in men with typical and atypical intermittent claudication (IC) according to Rose's questionnaire.

METHODS

Leg blood flow during reactive hyperaemia was assessed at 55 years of age by calf plethysmography. Measurement of the systolic ankle-arm pressure index was used to assess the prevalence of peripheral arterial disease (PAD) at 68 years of age. Mortality and incidence of cardiac events is based on record linkage with regional and national registers.

RESULTS

Twenty-one (3%) out of 700 men had typical IC at 55 years of age. Sixteen (76%) of these had normal plethysmography, with a mean peak flow (95% CI) of 24.6 (19.3-30.0) ml/min/100 ml. Peak flows were similar and normal in men with atypical IC (mean 22.5; 95% CI 21.3-23.6) and men having no pain (mean 23.8; 95% CI 23.1-24.4). Mortality rates were increased in men with typical IC but who had normal leg blood flow (49.5 deaths/1000 person years; p = 0.008), and men having atypical IC (35.3 deaths/1000 person years; p = 0.007) in comparison with men having no leg pain (27.4 deaths/1000 person years). This could not be accounted for by an increased cardiac event rate. The prevalence of PAD at 68 years of age was not increased in either of these two groups.

CONCLUSIONS

Only 12% of subjects with exertional pain fulfilled all criteria for typical IC. Typical and atypical claudication in absence of objective evidence of PAD was associated with a reduced life expectancy, but not with an increased cardiovascular risk. To properly assess the prognosis, non-invasive assessment of PAD should be used in addition to questionnaires.

Lung function, insulin resistance and incidence of cardiovascular disease: a longitudinal cohort study

OBJECTIVES

To explore whether a reduced lung function is a risk factor for developing diabetes and insulin resistance (IR), and whether such relationship contributes to the largely unexplained association between lung function and incidence of cardiovascular disease (CVD).

DESIGN

Forced vital capacity (FVC) was assessed at baseline. Incidence of diabetes and IR [according to the homeostasis model assessment (HOMA) model] was assessed in a follow-up examination after 13.9 +/- 2.6 and 9.4 +/- 3.6 years for men and women, respectively. After the follow-up examination, incidence of CVD (stroke, myocardial infarction or cardiovascular death) was monitored over 7 years.

SETTING

Populations-based cohort study.

SUBJECTS

Initially nondiabetic men (n = 1436, mean age 44.6 years) and women (n = 896, mean age 49.8 years).

RESULTS

Prevalence of IR at the follow-up examination was 34, 26, 21 and 21%, respectively, for men in the first (lowest), second, third and fourth quartile of baseline FVC (P for trend <0.0001). The corresponding values for women were 30, 29, 25 and 17%, respectively (P for trend <0.001). Adjusted for potential confounders, the odds ratio (OR) for IR (per 10% increase in FVC) was 0.91 (CI: 0.84-0.99) for men and 0.89 (CI: 0.80-0.98) for women. FVC was similarly significantly associated with the incidence of diabetes (OR = 0.90, CI: 0.81-1.00), adjusted for sex and other confounders. The incidence of CVD after the follow-up examination was significantly increased only amongst subjects with low FVC who had developed IR (RR = 1.7, CI: 1.02-2.7).

CONCLUSION

Subjects with a moderately reduced FVC have an increased risk of developing IR and diabetes. This relationship seems to contribute to the largely unexplained association between reduced lung function and incidence of CVD.

Is blood pressure at 68 an independent predictor of cognitive decline at 81? Results from follow-up study "Men born in 1914", Malmö, Sweden

One hundred and sixty-eight men who were participants in the study "Men born in 1914" had their blood pressure and cognitive function examined when they were 68 years old. They were then re-examined at the age of 81. Decline on five standardized cognitive tests at the age of 81 years was studied in relation to four levels of baseline blood pressure at the age of 68. Results from multivariate analyses suggested that blood pressure, when studied in conjunction with other factors related to cognitive function, contribute to a rather modest extent and not unambiguously to the variability in cognitive decline. When decline on each separate test had been combined into a composite measure, where equal weight had been given to memory, crystallized and fluid abilities, it was shown that hypertension stage 2 (SBP 160-179 mmHg or DBP 100-109 mmHg) was associated with greater levels of overall decline. Hypertension stage 3 (SBP > or =180 mmHg or DBP > or =110 mmHg), on the other hand, was associated with lower levels of overall decline. Depressive symptoms at follow-up had a negative effect on cognitive levels and were discussed as potential confounders of hypertension-related cerebral lesions.

Work-related psychosocial factors and carotid atherosclerosis

BACKGROUND

In order to better understand the role of work environment in the earlier stages of the cardiovascular disease process, we wanted to investigate the influence of work-related psychosocial factors on preclinical atherosclerosis.

METHODS

Cross-sectional data was used to examine the association between psychological job demands, job decision latitude, and carotid atherosclerosis in 2658 vocationally-active Swedish men and women, ages 46-65, from the general population. Odds ratios of carotid plaque prevalence and carotid artery intima-media thickness (IMT), determined by B-mode ultrasound, were estimated across combinations of job demands and decision latitude.

RESULTS

Women in job situations with high demands and low decision latitude ('job strain') showed a high plaque prevalence odds (odds ratio [OR] = 1.68, 95% CI: 1.14, 2.48), and a thicker IMT in the carotid bifurcation area (mean difference: 0.15 mm, 95% CI: 0.07, 0.23) compared with women in job situations with low demands and high decision latitude ('relaxed'). Adjustment for covariates only slightly reduced the magnitude of these associations. No such associations were seen in men. However, women in job situations with high demands and high decision latitude ('active') also showed high odds for carotid plaque, and a thicker IMT in the carotid bifurcation, compared with women in 'relaxed' job situations. In men, those in 'active' job situations had a low carotid plaque prevalence odds, while IMT in the carotid bifurcation did not differ from those in 'relaxed' job situations. Results showed only weak associations with IMT in the common carotid artery (CCA) in both men and women.

CONCLUSION

The specific hypothesis that high job demands interact synergistically with low decision latitude in the development of carotid atherosclerosis could not be supported in this study, neither in men nor in women. Instead a more complex pattern of interaction between job demands and decision latitude was shown.

Variability of fish consumption within the 10 European countries participating in the European Investigation into Cancer and Nutrition (EPIC) study

OBJECTIVE

To describe and compare the consumption of total fish (marine foods) and the fish sub-groups - white fish, fatty fish, very fatty fish, fish products and crustacea, in participants from the European Investigation into Cancer and Nutrition (EPIC) study.

DESIGN

Cross-sectional analysis of dietary intake using a computerised standardised 24-hour recall interview. Crude means, means and standard errors adjusted by age, season and day of the week were calculated, stratified by centre and gender.

SETTING

Twenty-seven redefined centres in the 10 European countries participating in the EPIC study.

SUBJECTS

In total, 35 955 subjects (13 031 men and 22 924 women), aged 35-74 years, selected from the main EPIC cohort.

RESULTS

A six- to sevenfold variation in total fish consumption exists in women and men, between the lowest consumption in Germany and the highest in Spain. Overall, white fish represented 49% and 45% of the intake of total fish in women and men, respectively, with the greatest consumption in centres in Spain and Greece and the least in the German and Dutch centres. Consumption of fatty fish reflected that of total fish. However, the greatest intake of very fatty fish was in the coastal areas of northern Europe (Denmark, Sweden and Norway) and in Germany. Consumption of fish products was greater in northern than in southern Europe, with white fish products predominating in centres in France, Italy, Spain, The Netherlands and Norway. Intake of roe and roe products was low. The highest consumption of crustacea was found in the French, Spanish and Italian centres. The number of fish types consumed was greater in southern than in northern Europe. The greatest variability in consumption by day of the week was found in the countries with the lowest fish intake.

CONCLUSIONS

Throughout Europe, substantial geographic variation exists in total fish intake, fish sub-groups and the number of types consumed. Day-to-day variability in consumption is also high.

Meat consumption in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts: results from 24-hour dietary recalls

OBJECTIVE

To evaluate meat intake patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts.

DESIGN AND SETTING

24-Hour dietary recalls were assessed within the framework of a prospective cohort study in 27 centres across 10 European countries by means of standardised computer-assisted interviews.

SUBJECTS

In total, 22 924 women and 13 031 men aged 35-74 years.

RESULTS

Mean total meat intake was lowest in the 'health-conscious' cohort in the UK (15 and 21 g day-1 in women and men, respectively) and highest in the north of Spain, especially in San Sebastian (124 and 234 g day-1, respectively). In the southern Spanish centres and in Naples (Italy), meat consumption was distinctly lower than in the north of these countries. Central and northern European centres/countries showed rather similar meat consumption patterns, except for the British and French cohorts. Differences in the intake of meat sub-groups (e.g. red meat, processed meat) across EPIC were even higher than found for total meat intake. With a few exceptions, the Mediterranean EPIC centres revealed a higher proportion of beef/veal and poultry and less pork or processed meat than observed in central or northern European centres. The highest sausage consumption was observed for the German EPIC participants, followed by the Norwegians, Swedish, Danish and Dutch.

CONCLUSIONS

The results demonstrate distinct differences in meat consumption patterns between EPIC centres across Europe. This is an important prerequisite for obtaining further insight into the relationship between meat intake and the development of chronic diseases.

Obesity and myocardial infarction--vulnerability related to occupational level and marital status. A 23-year follow-up of an urban male Swedish population

BACKGROUND

People, who are single, have a blue-collar job or low income have an increased cardiovascular risk. This study on myocardial infarction sought to explore whether the socio-economic pattern of disease has any relationship with obesity.

METHODS

In the cohort are 20,099 middle-aged men of whom 9,150 were manual and 9,190 nonmanual workers and 1,759 were self-employed. A total of 4,081 were single, 16,018 cohabiting. The body mass index (BMI) cut-off values for overweight and obesity were 25-30 and >/=30 kg m-2, respectively. Local and national registers were used to monitor incidence of events over 18 years.

RESULTS

Obesity was associated with an increased incidence of coronary events and deaths in each occupational group. Being single significantly increased the risk associated with obesity. After stratification for civil status the risk associated with obesity was limited to those who were single and who either had a blue-collar job or were self-employed. The multivariate-adjusted relative risk (RR) of coronary events and deaths in obese manual workers who were single was 1.91 (95% confidence interval: 1.21-3.02) and 2.54 (1.74-3.69), respectively, times higher than it was amongst those who were cohabiting. Amongst those who were self-employed, the corresponding age-adjusted RRs were 4.79 (1.69-13.57) and 3.80 (1.62-8.93).

CONCLUSIONS

Adjusted for lifestyle and biological risk factors, the increased risk of coronary events and death for obese men with manual jobs was applicable only to those who were single. It is concluded that being single significantly increases the cardiovascular risk associated with obesity.

Long-term effects of inflammation-sensitive plasma proteins and systolic blood pressure on incidence of stroke

BACKGROUND AND PURPOSE

The present study investigated the relationships between inflammation-sensitive plasma proteins (ISPs) and systolic blood pressure (SBP), as well as the joint long-term effects of ISP and SBP on incidence of stroke.

METHODS

BP and 5 ISPs (fibrinogen, alpha1-antitrypsin, haptoglobin, ceruloplasmin, orosomucoid) were assessed in 6071 healthy men 28 to 61 years of age. All-cause mortality and incidence of stroke were monitored over a mean follow-up of 18.7 years in men defined by SBP (<120, 120 to 139, >/=140 mm Hg) and ISP (0 to 1 or 2 to 5 ISPs in the top quartile).

RESULTS

SBP and diastolic BP were significantly and positively associated with the number of ISPs in the top quartile. As expected, elevated SBP was associated with an increased incidence of stroke. Among men with SBP >/=140 mm Hg, there were, however, significant differences between those with high and low ISP levels. After risk factor adjustment, men with SBP >/=140 mm Hg and high ISP levels had a relative risk of stroke of 4.3 (95% CI, 2.3 to 7.8) compared with men with SBP <120 mm Hg and low ISP levels. In the absence of high ISP levels, the risk associated with SBP >/=140 was 2.5 (95% CI,1.4 to 4.6). Men with high ISP levels had a significantly increased risk of stroke also after exclusion of the events from the first 10 years of follow-up.

CONCLUSIONS

High ISP levels are associated with elevated BP. These proteins are associated with an increased risk of stroke among men with high BP and provide information on stroke risk even after many years of follow-up.

Lung function and cardiovascular risk: relationship with inflammation-sensitive plasma proteins

BACKGROUND

The inverse relationship between pulmonary function and incidence of cardiovascular disease remains largely unexplained. This prospective study explored the hypothesis of a relationship with inflammation-sensitive plasma proteins.

METHODS AND RESULTS

Forced vital capacity (FVC) and plasma levels of fibrinogen, alpha(1)-antitrypsin, haptoglobin, ceruloplasmin, and orosomucoid were determined in 5064 healthy men aged 28 to 61 years. All-cause mortality, cardiovascular mortality, and incidence of myocardial infarction were monitored over a mean follow-up period of 18.4 years. Low FVC (fourth quartile) was associated with higher protein levels and with increased incidences of myocardial infarction and cardiovascular death. Adjustments for protein levels reduced the age-adjusted relative risks (RRs) for myocardial infarction (from 1.99, 95% CI 1.5 to 2.6, to 1.70, 95% CI 1.3 to 2.2) and cardiovascular death (from 2.71, 95% CI 1.9 to 3.9, to 2.28, 95% CI 1.6 to 3.3) among men with low FVC, corresponding to approximately 25% of the excess risk. The risk factor-adjusted RRs were reduced from 1.45 (95% CI 1.1 to 1.9) to 1.38 (95% CI 1.1 to 1.8) and from 1.96 (95% CI 1.4 to 2.8) to 1.85 (95% CI 1.3 to 2.7) for myocardial infarction and cardiovascular death, respectively, corresponding to approximately 10% to 15% of the excess risk. Among men with low FVC, the risk factor-adjusted RR for myocardial infarction was 2.5 (95% CI 1.7 to 3.6) for those with high protein levels (> or =2 proteins in top quartile) and 1.7 (95% CI 1.1 to 2.4) for those with low protein levels (< or =1 protein in top quartile; reference, top quartile of FVC and low protein levels).

CONCLUSIONS

FVC is significantly and inversely associated with plasma levels of inflammation-sensitive plasma proteins. This relationship contributes to but cannot fully explain the increased cardiovascular risk among men with low FVC.

Myocardial infarction in an urban population: worse long term prognosis for patients from less affluent residential areas

STUDY OBJECTIVE

The objective in this follow up study from the Malmö myocardial infarction register has been to assess whether long term survival following discharge after first myocardial infarction has any relation with the socioeconomic environment and to assess to what extent intra-urban differences in mortality from ischaemic heart disease can be accounted for by covariance with long term survival following discharge after acute myocardial infarction.

DESIGN

Register based surveillance study.

SETTING

Seventeen residential areas in the city of Malmö, Sweden.

PARTICIPANTS

The cohort contains all 2931 male and 2083 female patients with myocardial infarction who were discharged for the first time between 1986-95 from Malmö University Hospital.

MAIN RESULTS

During the on average 4.9 years of follow up 55% of the patients died. The sex adjusted and age adjusted all cause mortality rate/1000 patient years ranged between residential areas from 85.5 to 163.6. The area specific relative risk of death after discharge was associated with a low socioeconomic score, r=-0.56, p=0.018. Major risk factors for cardiovascular disease were more prevalent in areas with low socioeconomic score and low rates of survival. Of the intra-urban differences in mortality from ischaemic heart disease, 41% could be accounted for by differences with regard to the survival rate after discharge.

CONCLUSIONS

The results are compatible with the hypothesis that the socioeconomic environment plays an important part in the survival rate of patients with myocardial infarction. To assess the preventive potential, the extent to which socioeconomic circumstances covary with severity of disease, respectively with the use and compliance with secondary preventive measures, needs to be evaluated.

Influence of obesity on cardiovascular risk. Twenty-three-year follow-up of 22,025 men from an urban Swedish population

OBJECTIVE

To assess to what extent the incidence of coronary events and death related to smoking, hypertension, hyperlipidemia and diabetes is modified by obesity.

DESIGN

Prospective cohort study.

SUBJECTS

A total of 22 025 men aged 27 to 61-y-old at entry.

MEASUREMENTS

Incidence of coronary events (CE, ie acute myocardial infarctions and deaths due to chronic ischaemic heart disease) and death during 23 y of follow-up was studied in relation to body mass index (BMI), heart rate, blood pressure, blood lipids, glucose and insulin, lifestyle factors, history of angina pectoris, history of cancer, self-reported health and socio-economic conditions.

RESULTS

At the end of follow-up 20% of the obese men were no longer alive, and 13% had had a coronary event. Incidence of CE was 16% lower (RR (relative risk) 0.84; 95% confidence interval (CI) 0.65-1.10) among underweight (n=1171), 24% higher (RR 1.24; CI 1.12-1.37) among overweight (n=7773), and 76% higher (RR 1.76; 95% CI 1.49-2.08) among obese men (n=1343) than it was among men with normal BMI (n=11 738). The risk associated with overweight and obesity remained statistically significant after adjustment for potential confounders (RR 1.18; CI 1.07-1.31; and 1.39; 1.17-1.65, respectively). The association between BMI and mortality was J-shaped. In all, 1.7% of the obese men were smokers with hypertension, hyperlipidaemia and diabetes, 16.3% were not exposed to any of these risk factors. The cardiovascular risk associated with obesity was small in the absence of other risk factors. Between smoking and obesity there was a statistically significant synergistic effect.

CONCLUSIONS

Obesity is associated with an increased incidence of coronary events and death. The risk associated with obesity is substantially increased by exposure to other atherosclerotic risk factors, of which smoking seems to be the most important. The preventive potential of these associations should be evaluated in controlled trials.

Effects of cholesterol and inflammation-sensitive plasma proteins on incidence of myocardial infarction and stroke in men

BACKGROUND

Although cholesterol is a major cardiovascular risk factor, its association with stroke remains controversial. This study explored whether the cholesterol-related incidence of stroke and myocardial infarction is modified by plasma markers of inflammation in a large, population-based cohort with a long follow-up.

METHODS AND RESULTS

Plasma cholesterol and 5 inflammation-sensitive plasma proteins (ISP) (fibrinogen, alpha1-antitrypsin, haptoglobin, ceruloplasmin, and orosomucoid) were determined in 6063 healthy men, 28 to 61 years of age. The incidence of stroke, cardiac events (fatal and nonfatal), and cardiovascular deaths was compared between groups defined by levels of cholesterol and ISP. Mean follow-up was 18.7 years. High ISP level was defined as 2 to 5 ISP in the top quartile. High cholesterol was associated with higher levels of ISP. Hypercholesterolemia (> or =6.5 mmol/L, 251 mg/dL) was associated with an increased incidence of ischemic stroke and cardiac events and with a reduced incidence of intracerebral hemorrhage. The ISP levels modified these associations. After risk factor adjustment, men with hypercholesterolemia and high ISP levels had a significantly higher risk of cardiovascular death (relative risk [RR]=2.4; CI, 1.8 to 3.3), cardiac events (RR=2.3; CI, 1.8 to 3.0), and ischemic stroke (RR=2.1; CI, 1.4 to 3.3) than men with normal cholesterol and low ISP levels. In the absence of high ISP levels, hypercholesterolemia was associated with a moderately higher risk of cardiovascular death (RR=1.4; CI, 1.0 to 2.0) and cardiac events (RR=1.5; CI, 1.2 to 1.9) but not significantly with ischemic stroke (RR=1.25; CI, 0.8 to 2.0).

CONCLUSIONS

Hypercholesterolemia is associated with high plasma levels of ISP. These proteins increase the cholesterol-related incidence of cardiovascular diseases. In the absence of elevated ISP levels, no statistically confirmed association was found between hypercholesterolemia and ischemic stroke.

Insulin resistance in non-diabetic subjects is associated with increased incidence of myocardial infarction and death

AIMS

To compare the incidence of myocardial infarction and death in non-diabetic subjects with and without insulin resistance.

METHODS

Population-based prospective cohort study, in Malmö, Sweden, of 4748 non-diabetic subjects (60% women), aged 46-68 years, with no history of myocardial infarction or stroke. The prevalence of insulin resistance was established by the homeostasis model assessment (HOMA) and defined as values above the sex-specific 75th percentile (1.80 for women and 2.12 for men). Incidence of myocardial infarction and death is based on record linkage with local and national registers. Cox's proportional hazards model was used to assess the influence of insulin resistance after adjustment for age, sex, hyperglycaemia, raised arterial blood pressure, dyslipidaemia, central obesity, smoking and leisure-time physical activity.

RESULTS

Sixty-two subjects suffered a coronary event, and 93 subjects died during the 6-year follow-up period. Insulin resistance was after adjustment for other factors included in the insulin resistance syndrome and other potential confounders, associated with an increased incidence of coronary events (relative risk (RR) 2.18; 95% confidence interval (CI) 1.22-3.87; P = 0.008) and deaths (RR 1.62; 1.03-2.55; P = 0.038).

CONCLUSIONS

Insulin resistance, as assessed by the HOMA method, was in this cohort of middle-aged non-diabetic subjects associated with an increased incidence of myocardial infarction and death. This risk remained when smoking, low physical activity and factors included in the insulin resistance syndrome were taken into account in a stepwise regression model.

Risk of developing diabetes is inversely related to lung function: a population-based cohort study

AIM

To investigate whether reduced lung function is a risk factor for developing diabetes.

METHODS

Non-diabetic men (n = 382) from the population-based cohort 'Men Born in 1914' were examined with spirometry at age 55 years. The cohort was re-examined at 68 years. Diabetes and fasting plasma glucose at follow-up were studied in relation to vital capacity (VC) and forced expiratory volume (FEV1.0) at baseline.

RESULTS

Fifteen men developed diabetes during the follow-up. The percentage with diabetes in the 1st, 2nd, 3rd and top quartile of vital capacity were 7%, 5%, 2%, and 1%, respectively (P for trend = 0.01). Fasting glucose (log transformed, mmol/l) at follow-up was 1.63 +/- 0.16, 1.62 +/- 0.18, 1.61 +/- 0.11 and 1.60 +/- 0.11, respectively (P for trend = 0.11). The longitudinal associations between VC and diabetes (P = 0.001) and log glucose (P = 0.036) were significant after adjustments for several potential confounders. FEV(1.0) at baseline showed similar associations with diabetes at follow-up.

CONCLUSIONS

The risk of developing diabetes is inversely associated with pulmonary function among middle-aged men.

Food patterns and components of the metabolic syndrome in men and women: a cross-sectional study within the Malmö Diet and Cancer cohort

This study examined the relations between food patterns and five components of the metabolic syndrome in a sample of Swedish men (n = 2,040) and women (n = 2,959) aged 45-68 years who joined the Malmö Diet and Cancer study from November 1991 to February 1994. Baseline examinations included an interview-administered diet history, a self-administered questionnaire, blood pressure and anthropologic measurements, and blood samples donated after an overnight fast. Cluster analysis identified six food patterns for which 43 food group variables were used. Logistic regression analysis was used to examine the risk of each component (hyperinsulinemia, hyperglycemia, hypertension, dyslipidemia, and central obesity) and food patterns, controlling for potential confounders. The study demonstrated relations, independent of specific nutrients, between food patterns and hyperglycemia and central obesity in men and hyperinsulinemia in women. Food patterns dominated by fiber bread provided favorable effects, while food patterns high in refined bread or in cheese, cake, and alcoholic beverages contributed adverse effects. In women, food patterns dominated by milk-fat-based spread showed protective relations with hyperinsulinemia. Relations between risk factors and food patterns may partly depend on gender differences in metabolism or food consumption and on variations in confounders across food patterns.

The Malmö Diet and Cancer Study: representativity, cancer incidence and mortality in participants and non-participants

In order to investigate potential selection bias in population-based cohort studies, participants (n = 28098) and non-participants (n = 40807) in the Malmö Diet and Cancer Study (MDCS) were compared with regard to cancer incidence and mortality. MDCS participants were also compared with participants in a mailed health survey with regard to subjective health, socio-demographic characteristics and lifestyle. Cancer incidence prior to recruitment was lower in non-participants, Cox proportional hazards analysis yielded a relative risk (RR) with a 95% confidence interval of 0.95 (0.90-1.00), compared with participants. During recruitment, cancer incidence was higher in non-participants, RR: 1.08 (1.01-1.17). Mortality was higher in non-participants both during, 3.55 (3.13-4.03), and following the recruitment period, 2.21 (2.03-2.41). The proportion reporting good health was higher in the MDCS than in the mailed health survey (where 74.6% participated), but the socio-demographic structure was similar. We conclude that mortality is higher in non-participants than in participants during recruitment and follow-up. It is also suggested that non-participants may have a lower cancer incidence prior to recruitment but a higher incidence during the recruitment period.

A comparison of cognitive ability in normotensive and hypertensive 68-year-old men: results from population study "men born in 1914," in Malmö, Sweden

Hypertension and its consequences on cognition was analyzed using data from the study "Men born in 1914" in Malmö, Sweden, a prospective cohort study of cardiovascular disease. The baseline examinations took place in 1982/83 where 500 men participated in extensive medical and social examinations. A neuropsychological investigation was completed including five standardized cognitive tests. The specific purpose of the study was to investigate whether hypertension was associated with cognitive performance. By the use of multiple regression analyses, normal blood pressure and three stages of hypertension were analyzed in relation to test performance. Hypertension Stage 3 was associated with lower performance on tests measuring psychomotor speed and visuospatial memory, whereas hypertension Stage 1 was associated with higher performance on tests measuring verbal ability and constructional ability. The associations were unconfounded by clinical manifestations of atherosclerosis, history of stroke, depressive mood, and antihypertensive drug treatment.

Nonattendance in mammographic screening: a study of intraurban differences in Malmö, Sweden, 1990-1994

Mammographic screening may reduce breast cancer mortality. Not all women, however, come for examination. The objective in this study from Malmö has been to assess extent to which the rate of nonattendance varies between residential areas with different sociodemographic profiles. The study is based on 32,605 women, 45 to 68 years old and living in 17 areas, who between 1990 and 1994 were invited to screening. Between age groups, the age-specific nonattendance rate ranged from 31% to 35 % (P < .01). The nonattendance rate was highest for women 65 years or older. Between residential areas, age-adjusted nonattendance rates ranged from 23% to 43% (P < .01). A socioeconomic score was developed to express the socioeconomic circumstances in the residential areas and ranged from -7.18 in the most deprived area to 5.01 in the least. Nonattendance covaried in an inverse fashion with the socioeconomic score (r = -0.78; P < .01). One of three women in this urban population did not accept the invitation to mammographic screening. Our conclusion is that women in areas with less favorable circumstances seem to be less willing to participate.

Geographical pattern of female deaths from myocardial infarction in an urban population: fatal outcome out-of-hospital related to socio-economic deprivation

OBJECTIVE

This study of myocardial infarction (MI) amongst urban women has sought to assess whether there are differences in fatal outcome, in-hospital respectively out-of-hospital, between residential areas defined in terms of socio-economic circumstances.

DESIGN

Register-based surveillance study 1986-95.

SETTING

Seventeen residential areas in the city of Malmö, Sweden.

SUBJECTS

Women 20-74 years of age.

MAIN OUTCOME MEASURES

Differences in fatal outcome, in-hospital respectively out-of-hospital, between residential areas were expressed in terms of age-adjusted odds ratios (ORs), calculated by means of logistic regression. Socio-economic circumstances in the areas were expressed in terms of a composite score.

RESULTS

Between residential areas there were marked and statistically significant differences in incidence (range 124-328/10(5), P < 0.001, d.f.=16) and mortality (range 38-132/10(5), P < 0.005, d.f.=16). Area rates of mortality covaried with incidence (r=0.85, P < 0.001) and with odds ratios of fatal outcome out-of-hospital (r=0.52, P=0.031) but not in-hospital. The odds ratios of fatal outcome out-of-hospital decreased in a statistically significant stepwise fashion from areas in the lowest socio-economic quintile (reference) to areas in the highest socio-economic quintile (OR: 0.67, 95% CI: 0.48-0.94). There was no corresponding association with the odds ratios of fatal outcome in-hospital.

CONCLUSIONS

The high rate of mortality from MI amongst women in areas with deprived socio-economic circumstances was related to deaths occurring out-of-hospital. In order to assess the preventive potential there is a need for further studies that may clarify to what extent the association with socio-economic circumstances can be explained by other factors and conditions known to influence the probability of survival.

Adaptive behavior in stressful situations and stroke incidence in hypertensive men: results from prospective cohort study "men born in 1914" in Malmö, Sweden

BACKGROUND AND PURPOSE

Although hypertension is a major risk factor for stroke, many hypertensive persons remain healthy. The aim of the present study was to analyze whether adaptation in a stressful situation was associated with the incidence of stroke in hypertensive men.

METHODS

Two hundred thirty-eight hypertensive men were followed from baseline in 1982/1983 until first stroke, death, or December 31, 1996. Adaptation to stress was studied with the serial Color-Word Test. In the Regression dimension, 4 patterns of adaptation could be distinguished according to mastering of the test. Successful mastering of the test was shown in stabilized patterns, increasing difficulty in cumulative patterns, fluctuating difficulty in dissociative patterns, and fluctuating difficulty that increased during testing in cumulative-dissociative patterns. The patterns were compared regarding stroke incidence.

RESULTS

Forty-three men experienced a stroke during follow-up. Stroke rates per 1000 person-years were 12.6 for men with stabilized patterns, 14.3 for men with cumulative patterns, 16.2 for men with dissociative patterns, and 31.2 for men with cumulative-dissociative patterns. Multivariate analysis, adjusted for relevant cerebrovascular risk factors, showed that the cumulative-dissociative pattern of the Regression dimension was associated with an increased risk of stroke during follow-up (relative risk 3.00, 95% CI 1.32 to 6.81).

CONCLUSIONS

The specific behavior pattern, characterized by the greatest difficulties in managing the test, was associated with incidence of stroke in hypertensive men. One interpretation is that hypertensive men who chronically fail to find successful strategies in stressful situations are vulnerable to the damaging effects of stress and thereby at an increased risk of a future stroke.

Blood pressure increase between 55 and 68 years of age is inversely related to lung function: longitudinal results from the cohort study 'Men born in 1914'

BACKGROUND

Although age is associated with increasing blood pressure, there is a substantial heterogeneity within a certain birth cohort. Whether increase in systolic and diastolic blood pressure is related to pulmonary function is largely unknown.

OBJECTIVE

To study blood pressure elevation between 55 and 68 years of age in relation to vital capacity (VC) and forced expiratory volume (FEV1.0) at 55.

DESIGN

Population-based cohort study.

PARTICIPANTS

A total of 375 men without antihypertensive medication at baseline.

MAIN OUTCOME MEASURE

Change in systolic blood pressure (SBP) and diastolic blood pressure (DBP) over 13 years.

RESULTS

Blood pressure increase between 55 and 68 years was highest among men who at 55 years had low vital capacity. Average increase in systolic blood pressure for men with vital capacity in the first, second, third and fourth quartile was 20.4, 18.7, 16.5 and 11.1 mmHg, respectively (P for trend = 0.005). Average increase in diastolic blood pressure was 10.6, 9.9, 9.0 and 6.3 mmHg, respectively (P= 0.02). The trends remained statistically significant after adjustments for baseline blood pressure, tobacco consumption, smoking cessation between 55 and 68, weight change between 55 and 68, physical activity and diabetes. Further analysis showed that the relationships could be found among men with blood pressures < or = 140/ 90 mmHg at baseline, whereas no significant association was found for men whose baseline SBP or DBP exceeded 140/90 mmHg. FEV1.0 showed similar associations with change in blood pressure.

CONCLUSION

Lung function is inversely associated with future blood pressure increase. It is suggested that this association could contribute to the relationships between lung function and incidence of cardiovascular disease.

Increased incidence of small and well-differentiated breast tumours in post-menopausal women following hormone-replacement therapy

Exposure to hormone-replacement therapy (HRT) has consistently been associated with an increased incidence of breast cancer, particularly of small tumours. Other tumour characteristics in relation to HRT have received less scientific attention. Our aim in this population-based prospective cohort study was to assess whether HRT is associated with an increased incidence of breast-cancer subgroups defined in terms of stage, type (according to the WHO system), Nottingham grade and the Nottingham Prognostic Index (NPI). Evaluation was based on a cohort of 5,865 post-menopausal women followed for an average of 9.8 years. Twenty percent of women reported current use of HRT at the time of the baseline interview. Record linkage with the Swedish Cancer Registry and local clinical registries identified 141 incident invasive breast-cancer cases. All tumours were reclassified by 1 pathologist. The incidence of breast cancer in HRT users was 377/10(5) and in non-users 221/10(5) person-years [relative risk (RR) = 1.72, 95% confidence interval (CI) 1.17-2.52]. This risk remained statistically significant after adjustment for established risk factors in a Cox proportional hazards analysis (RR = 1.66, 95% CI 1.12-2.45). Among HRT users, there was over-representation of cases with stage I tumours (adjusted RR = 2.33, 95% CI 1.44-3.76), of lobular carcinomas (RR = 4.38, 95% CI 1.60-12.0) and of tubular tumours (RR = 4.81, 95% CI 1.37-16.8). Nottingham grade I/II carcinomas (RR = 2.02, 95% CI 1.29-3.16) and cases with NPI < or = 3.4 (RR = 2.29, 95% CI 1.41-3.72) were similarly over-represented among HRT users. Incidence of breast cancer was increased in post-menopausal women who used HRT at baseline. Among HRT users, there was over-representation of tumours that, with regard to stage, type and grade, are associated with a favourable prognosis.

Occurrence and prognostic significance of ventricular arrhythmia is related to pulmonary function: a study from "men born in 1914," Malmö, Sweden

BACKGROUND

Reduced lung function has been associated with increased rates of myocardial infarction. Whether the occurrence and prognostic significance of ventricular arrhythmia is related to lung function is largely unknown.

METHODS AND RESULTS

We performed a population-based study of 68-year-old men without a history of stroke or myocardial infarction; 402 men participated. Mortality and coronary events (fatal or nonfatal) were studied in relation to ventricular arrhythmia during 24 hours, percentage of the predicted forced expiratory volume (FEV1(%pred)), vital capacity (VC(%pred)), and the FEV/VC ratio. During 14 years of follow-up, 181 men died and 87 experienced a coronary event. Occurrence of frequent or complex ventricular arrhythmia (Lown class 2 to 5) was significantly and inversely associated with FEV1(%pred). Men with Lown class 2 to 5 and a low FEV1(%pred) (below median) had significantly higher mortality (71.5 versus 26.8 per 1000 person-years; P<0.0001) and coronary event rates (37.7 versus 18.0; P=0.02) than men with Lown class 2 to 5 and a high FEV1(%pred). These associations remained significant after adjustments for potential confounders (mortality: relative risk [RR], 2.91; 95% CI,1.68 to 5.04; coronary events: RR, 2.16; 95% CI, 1.07 to 4.37). In men without frequent or complex arrhythmia (Lown 0 to 1), a low FEV1(%pred) was not significantly associated with mortality (RR, 1.37; 95% CI, 0.92 to 2.05) or coronary events (RR, 1.24; 95% CI, 0.67 to 2.27) after adjustments for confounders. The FEV/VC ratio showed similar associations with arrhythmia, mortality, and coronary events.

CONCLUSIONS

Lung function is inversely associated with the occurrence of ventricular arrhythmia. The increased incidence of myocardial infarction and death associated with arrhythmia was mainly limited to men with a low FEV1(%pred) or FEV/VC. We suggest that lung function should be considered when assessing the prognostic significance of ventricular arrhythmia.

Breast cancer incidence in ex-smokers in relation to body mass index, weight gain and blood lipid levels

According to several studies breast cancer is more common among former smokers. This study explores whether this association has any relationship with anthropometric measurements or blood lipid levels. The 2082 ex-smokers (mean age 49.9 years) in the Malmö Preventive Cohort were followed for an average of 13.3 years using official cancer registries. This yielded 93 incident breast cancer cases. Oestrogen receptor (ER) status was assessed by an immunological method. Incidence of breast cancer covaried with height, body mass index, weight gain and cholesterol levels. None of these associations reached statistical significance. Incidence of breast cancer increased over quartiles of serum triglycerides, Ptrend: 0.02, relative risk (RR) for triglycerides as a continuous variable: 1.46 (1.21-1.77). Nineteen tumours were ER negative; this subgroup was similarly related to high triglycerides, 1.76 (1.40-2.21). All results were similar when BMI and cholesterol levels were entered into the model. It is concluded that breast cancer incidence covaries with triglyceride levels in ex-smokers.

Asymptomatic leg atherosclerosis is reduced by regular physical activity. Longitudinal results from the cohort "men born in 1914"

OBJECTIVE

To study whether physical activity is associated with reduced occurrence of asymptomatic leg atherosclerosis.

DESIGN

Longitudinal and cross-sectional analyses of the population-based cohort "men born in 1914".

METHODS

Comparison of the systolic ankle/arm pressure index (AAI) at age 68 in groups who were sedentary, performed some activity, and performed regular physical training at 55 and 68 years of age.

RESULTS

At 55 years of age, 100 (27%) were sedentary, 209 (58%) reported some physical activity and 54 (15%) reported regular physical training. At 68 years, 194 men (53%) reported the same degree of physical activity, 127 (35%) reported a higher physical activity, and 42 (12%) reported lower physical activity. Physical activity at 55 years (p =0.03) and increased physical activity between 55 and 68 years (p =0.03) were both associated with higher AAI at 68 after adjusting for potential confounders. At 68 years, AAI was 0.89+/-0.21, 1.01+/-0.13 and 1.05+/-0.11, respectively, in men who were sedentary, reported some physical activity, and regular physical training (p =0.0002). This association remained significant after adjustments for potential confounders.

CONCLUSIONS

regular physical activity is associated with reduced occurrence of asymptomatic leg atherosclerosis, even in men taking up exercise after age of 55.

Geographic distribution of stroke incidence within an urban population: relations to socioeconomic circumstances and prevalence of cardiovascular risk factors

BACKGROUND AND PURPOSE

Geographic differences in stroke incidence indicate a potential for prevention. The present study from the city of Malmö, Sweden, sought to investigate whether incidence of stroke in residential areas is related to prevalence of cardiovascular risk factors and socioeconomic circumstances.

METHODS

The Stroke Register in Malmö, Sweden, was used for retrieval of the 3540 patients who suffered a first stroke between 1989 and 1998. The Malmö Diet and Cancer cohort (n=28 466) was used to assess area specific prevalence of hypertension, diabetes, smoking, and being overweight and for computation of a cardiovascular risk score. Socioeconomic circumstances for the 17 administrative areas were expressed in terms of a composite score.

RESULTS

Standardized stroke incidence ranged among areas from 437 to 743 per 100 000 for men and from 223 to 518 per 100 000 for women. Socioeconomic score correlated significantly with area-specific stroke rates among men (r=-0.62, P=0.008) and women (r=-0.67, P=0.004). Incidence of stroke was significantly associated with cardiovascular risk score for each area (men, r=0.53, P<0.05; women, r=0.76, P<0.001). The cardiovascular score and the socioeconomic score together accounted for 44% of the geographic variance among men and 63% among women.

CONCLUSIONS

Marked differences occurred in stroke incidence among residential areas within this urban population. High-rate areas were characterized by a higher prevalence of smoking, hypertension, diabetes, and being overweight and by inferior socioeconomic circumstances. These risk factors accounted for a substantial proportion of the geographic variance in incidence of stroke.

Low-dose metoprolol CR/XL and fluvastatin slow progression of carotid intima-media thickness: Main results from the Beta-Blocker Cholesterol-Lowering Asymptomatic Plaque Study (BCAPS)

BACKGROUND

Statins reduce cardiovascular events and progression of carotid intima-media thickness (IMT). beta-Blockers are also known to reduce cardiovascular events, but less is known about their effects on carotid IMT.

METHODS AND RESULTS

We conducted a randomized, double-blind, placebo-controlled, single-center trial to compare the effects of low-dose metoprolol CR/XL (25 mg once daily) and fluvastatin (40 mg once daily) on the progression of carotid IMT during 36 months of treatment in 793 subjects who had carotid plaque but no symptoms of carotid artery disease. Changes in mean IMT in the common carotid artery and maximal IMT in the bulb were the main outcome variables. Death and cardiovascular events were monitored. Progression of IMT(max) in the carotid bulb at both 18 and 36 months was reduced by metoprolol CR/XL (-0.058 mm/y; 95% CI, -0.094 to -0.023; P=0.004; and -0.023 mm/y; 95% CI, -0.044 to -0.003; P=0.014, respectively). Incidence of cardiovascular events tended to be lower in metoprolol CR/XL-treated patients (5 versus 13 patients, P=0.055). Rate of IMT(mean) progression in the common carotid at 36 months was reduced by fluvastatin (-0.009 mm/y; 95% CI, -0.015 to -0.003; P=0.002). Women in the fluvastatin group had increased frequency of transiently high liver enzymes.

CONCLUSIONS

This is the first randomized trial to show that a beta-blocker can reduce the rate of progression of carotid IMT in clinically healthy, symptom-free subjects with carotid plaque. This suggests that beta-blockers may have a favorable effect on atherosclerosis development.